Communication Product Updates

Below are brief descriptions of communications products recently developed by the Federal Highway Administration’s (FHWA) Office of Research, Development, and Technology. All of the reports are or will soon be available from the National Technical Information Service (NTIS). In some cases, limited copies of the communications products are available from FHWA’s Research and Technology (R&T) Product Distribution Center (PDC).

When ordering from NTIS, include the NTIS publication number (PB number) and the publication title. You also may visit the NTIS Web site at www.ntis.gov to order publications online. Call NTIS for current prices. For customers outside the United States, Canada, and Mexico, the cost is usually double the listed price. Address requests to:

How can renewable electric power production reduce highway maintenance and operating costs while providing backup for critical systems during power outages? This fact sheet discusses using the public right-of-way and roadway infrastructure as a source for energy production, storage, and distribution. This fact sheet highlights a project sponsored by FHWA’s Exploratory Advanced Research (EAR) Program and awarded to the University of Nebraska–Lincoln to develop an intelligent power system.

Researchers are developing a combination wind and solar hybrid system that will connect to a traffic signal. Onsite wind turbines and solar panels will generate the power to not only operate the traffic signal but also to return excess energy to the electric power grid. This functionality could dramatically alter the role of transportation infrastructure in the public rights-of-way from an energy consumer to an energy producer.

The hybrid system is being developed for urban and suburban load centers, where the electric power will be used locally and not require additional investments in power distribution systems. Due to the intermittent and uncontrollable nature of wind and solar resources, the researchers will study historical data at potential locations to determine the type and size of equipment required for optimal performance.

The energy-plus signals will connect to the existing utility distribution grids in close proximity to form a small power grid, known as a microgrid. A power management system will manage production, storage, distribution, and consumption of energy based on demand within the grid using existing roadway communication and networking infrastructure. Each signal will be controlled by a local power management controller and will interact with other signals. The microgrid will in turn operate as a smart entity within the wider utility distribution grid.

This project could make it possible to significantly reduce the overall power needed to operate and maintain roadway systems and help create a more efficient network. The researchers will test and refine the system through modeling and simulation studies using a prototype at the University of Nebraska–Lincoln. They will incorporate traffic simulation software to assess the impact on efficiency, operational costs, and driver behavior.

Ultra-High Performance Concrete: A State-of-the-Art Report for the Bridge Community (Report)

Publication No. FHWA-HRT-13-060

Because of its strength and durability, ultra-high performance concrete (UHPC) offers new opportunities for highway infrastructure projects. This report documents state-of-the-art research, development, and deployment of UHPC components on highway infrastructure in the United States and internationally. The report also underscores what is needed to enable wider use of this concrete.

Higher compressive strength, higher tensile strength with ductility, increased durability, and higher initial unit cost distinguish UHPC from conventional concrete. When compression is the predominant design consideration, UHPC is ideal, and the sustained tensile capacity enables the design of more efficient, slender materials than conventional reinforced concrete. UHPC excels in outdoor and severe exposure environments. The concrete does have a higher initial unit cost than conventional concrete, but it can be optimized for applications (such as the reduction of shear reinforcement in a beam), eliminating some of the costs associated with conventional concrete applications. Also, the cost of UHPC should be considered over the life cycle of the concrete.

To encourage greater use of UHPC, the report recommends conducting studies to demonstrate the cost-effectiveness of UHPC in various applications and developing guide specifications for the design and construction of UHPC structures. Researchers also identified a need for guidelines for standard test methods, material specifications, and production procedures for precast and cast-in-place construction. Further still, the research team found that broader geographic distribution of demonstration projects and dissemination of technical information would help increase market penetration.

This report includes information about materials and production, mechanical properties, structural design and testing, prestressing, durability testing, and actual and potential applications. Also included are recommendations for the future direction of UHPC applications in the United States.

Lightweight Concrete: Mechanical Properties (TechBrief)

Publication No. FHWA-HRT-13-061

To advance the state of the practice with regard to high-strength concretes, researchers at FHWA’s Turner-Fairbank Highway Research Center investigated the performance of lightweight concretes with varying compressive strengths.

This TechBrief presents a summary of results from mechanical property tests of lightweight concrete conducted as part of an analysis of prestressed girders and reinforced concrete beams. Researchers combined these results with the broader body of knowledge on lightweight concrete performance to create a database, used to develop revised predictive relationships for this type of concrete. The document also offers potential revisions to the American Association of State Highway and Transportation Officials’ LRFD [Load and Resistance Factor Design] Bridge Design Specifications.

The study is part of a broader effort in which researchers used lightweight concrete with three different aggregates intended to represent those available in North America. Conducting tests on 27 precast/prestressed girders, the researchers investigated topics including transfer length and development length of prestressing strand, time-dependent prestress losses, and shear strength. The research team used 40 reinforced concrete beams to examine development and splice length of steel reinforcement used in girders and decks made with lightweight concrete.

The research focused on structural behavior and also included assessments of material characterizations including compressive and splitting tensile strength of the concrete mixes. A full description of the database and a discussion of the development and evaluation of prediction expressions are included in the full report Lightweight Concrete: Mechanical Properties (FHWA-HRT-13-062), which this document summarizes.

Corrosion reduces the service life of steel bridges and compromises public safety. Caused by exposure to moisture and atmospheric pollutants (particularly chlorides and sulfates), corrosion costs the United States an estimated $500 million annually based on a 2002 index of cost for maintenance and rehabilitation.

This fact sheet discusses an EAR-sponsored project conducted by the City College of New York to slow the deterioration of steel infrastructure with the help of safer, corrosion-resistant coatings. Researchers also are working to develop a model to assist bridge owners in setting optimal schedules for rehabilitating steel bridges.

The project aims to deliver a nanotechnology-based coating that meets these requirements at a lower life-cycle cost. In the first phase, researchers incorporated nanomaterials into two innovative coating systems. They used an epoxy system with polyaniline, a polymer with high electrical conductivity, and added carbon black to reduce the need to add zinc and to improve scratch resistance. They also used a calcium sulfonate alkyd system enhanced with nanoclay to improve corrosion and scratch resistance.

The researchers found that the polyaniline-epoxy system performed well in the short term under electrochemical impedance spectroscopy, which tests adhesion and corrosion performance. The nanoclay-enhanced calcium sulfonate alkyd system proved superior in adhesion strength, drying time, and scratch resistance, but corrosion resistance seemed compromised by uneven dispersal of nanoparticles.

In the second phase, now underway, the researchers will explore two alternative additives for the calcium sulfonate alkyd-based system and conduct accelerated testing and weathering studies of the calcium sulfonate alkyd- and epoxy-based coatings. Accelerated corrosion tests are equivalent to 20 years of field exposure that includes some elevated temperatures and exposure to salt, humidity, and sulfur dioxide. In the outdoor weathering study, with and without salt, periodic testing at five intervals will help characterize performance over 18 months. This comprehensive testing will determine the realistic life expectancy of the coating systems for steel bridges located in real-world environments.